1. Field of the Invention
The present invention relates to a method for controlling a driver assistance system and a driver assistance system.
2. Description of Related Art
Driver assistance systems are known which warn the driver of a vehicle before he leaves a traffic lane or support him in keeping to a chosen traffic lane. For this purpose, the driver assistance system includes assistance functions such as LDW (lane departure warning) and/or LKS (lane keeping support). Assistance function LDW warns the driver of leaving the traffic lane by generating optical and/or acoustic and/or haptic signals. Assistance function LKS intervenes actively in onboard systems of the vehicle, particularly in the steering system, in order to keep a vehicle, that is deviating from the traffic lane, in the traffic lane. For this purpose, the driver assistance system includes a sensor system including, in particular, at least one video sensor for detecting traffic lane markings or the like.
Driver assistance systems known up to now, having a transverse guidance function, such as LDW, LKS or an automatic transverse guidance in a traffic jam assistance system, attempt to guide the vehicle as much as possible to the middle of the traffic lane. Most drivers, however, perceive it rather as disagreeable to keep strictly accurately to the middle of their own traffic lane when a vehicle in an adjacent traffic lane is traveling very close to the boundary of their own traffic lane or even crosses the traffic lane boundary, and thus reaches onto their own traffic lane. This situation is perceived as being unpleasant or even threatening if the vehicle on the adjacent lane is a large vehicle, such as a commercial vehicle or a bus.
For the controlling of a driver assistance system, it is known from DE 102007015879.5 that one may monitor the vehicle environment for obstacles, and when an obstacle is detected, to change the setpoint trajectory of the vehicle in such a way that passing the detected obstacle without danger is made possible. A safety range assigned to each obstacle is preferably specified in this context, whose size may advantageously also depend on the size of the obstacle.
Furthermore, a driver assistance system having a lane keeping function is known from DE 102005048014.4, including a device for recognizing the traffic lane on the roadway, a control device for intervention in the steering system of the vehicle in the sense of lane holding, means being provided for detecting cornering of the vehicle. The control device exercises its control function as a function of the position of the vehicle in the traffic lane, and as a function of cornering.
A lane changing assistant is known from published German patent document DE 101 14 470 A1 that has a video system as its sensor device. Using the sensor device, traffic lane markings on the roadway are able to be detected, and with that, also the transverse position of one's own vehicle, with respect to the currently traveled traffic lane. If the transverse position of the vehicle deviates by more than a certain tolerance limit to one side or the other of the center of the lane, a regulating intervention in the steering automatically takes place, so as to return the vehicle approximately to the center of the lane. This raises driver comfort for the driver and also increases the travel safety, since the driver is able to concentrate completely on the traffic situation. If the driver deliberately wants to undertake a change of lane, however, for instance, for initiating a passing process, then, in the case of an active lane holding function, he has to exert a greater force on the steering wheel, in order to overcome the forces caused by the regulating intervention of the lane holding assistant. For this reason, it is provided in the known system that the lane holding function is deactivated at least temporarily when a lane change intention of the driver is detected, for example, with the aid of the operation of the turn signal indicator.
Moreover, a lane holding assistant for motor vehicles is known from DE 102 005 024 382.7 that has a sensor device for detecting the traffic lane on the roadway, having a control device which exerts a force on the steering of the vehicle via an actuator, so as to hold the vehicle in the lane, and having a device for recognizing the lane change intention of the driver. The control device, in this instance, is developed in such a way that when the lane change intention is detected, the force exerted on the steering system is able to be modified asymmetrically within the meaning of an easier lane change. Furthermore, when the lane change intention from one's own lane to a target lane has been detected, the amount of the force exerted upon the steering system of the vehicle is a function of the deviation of the vehicle from the setpoint trajectory in such a way that the force for transverse positions between the setpoint trajectory in one's own lane and the setpoint trajectory in the target lane is reduced or is equal to zero, but increases again on the other side of the setpoint trajectory of the target lane.
A device for determining the possibility of passage for a vehicle at obstacles is known from published German patent document DE 10 2004 015 749 A1, and it is used to estimate whether a vehicle is able to pass through between obstacles with respect to its height and/or its width. The device includes a sensor unit for measuring the passage width between obstacles and/or a passage height below obstacles and an evaluation unit, the passage width ascertained and/or the passage height ascertained being compared to a vehicle width and/or a vehicle height in such a way that a warning is emitted for the case in which the ascertained passage height and/or the ascertained passage width does not permit the passage of the vehicle at the obstacles.